17536: Fuel Trim: Bank 1 (Mult): System too Lean

[Martyn]

Vern, it's definately stage 2 mate.

I too have always been under the impression that the 2nd 02 sensor is ignored once stage 2 was loaded thus being able to run race cats/straight through pipes without throwing a CEL.

*Edit* You're too quick for me Vern

Looks like the car will be parked up until I can borrow or buy a new MAF

 

[vern]

your should be 210/220 bhp ish mate yeah???

I would want to see 165-175 G/S mate on maf

Get it in 3rd/4th and go for it to red line

on your current readings you are 185 ish bhp mate

 

[Martyn]

Vern, i'd of thought so taking into account the dyno lottery

With the same MAF the car ran 202bhp on Awesome's rollers on thurs but didnt really break 150g/s during the 3 runs..

 

[vern]

Vern, i'd of thought so taking into account the dyno lottery

With the same MAF the car ran 202bhp on Awesome's rollers on thurs but didnt really break 150g/s during the 3 runs..

I aint alway's right mate, but i think it's under reading......... and for £85 ish mate you can't go wrong, beats melting summat, i am 98% certain please post up let me know how you go


or why not pimp the forum? ask to meet up with someone and swap for an hour, loads of same motors on here. poss thread topic, help me or be banned

 

[Martyn]

Yea, its definately worth a go mate, just a shame its come at bank holiday time!

I'll have an ask around and if I can blag one for a few runs.

P.S. I'd never abuse my power lol

 

[m0rk]

i'm not sure to correctly understand what you write (not awaked enough to be sure to translate well ), but you mean you use a 3b fpr with stage 2 and all is ok with ecu adapting and using higher injection time ?

Martyn's log is quickly showing more than 10% for multiplicative trim and a max of 25% (which may be the max it can report seeing how it hit a wall on this perfect round up value), i don't think adaptation can deal with that kind of difference

i remember i have seen in one of your log that the maf values was low (with correct boost) it may explain that ecu managed to adapt without throwing a fault, do you have a log of block 32 to see your trim values ?

i'm sorry if i misunderstand

It's only running a std DP, so it's kind of pointless, but the fuelling is fine, as are FC's (none) and none of the stuff Marts is having.

No rough idle, no stalling, no limp mode (ever)

The adaptation is fine (I understood +/- 20% on injection times)

 

[Martyn]

Just replaced the pipe that runs from the Turbo Inlet Pipe to the throttle body as I though that might have been leaking but it still doesnt run any better.

Tomorrow we shall rule out the MAF as Glenn is kindly going to lend me his!

 

[PhilW]

I'll be interested to see the outcome of this as we've had similar results and problems, i got 209bhp and didnt break 150g/s on the rollers, stalling and i've previously had a similar code, lean, which was sorted due to my DV coming loose.

Good luck tho, hope it turns out ok.

 

[Martyn]

A massive thanks to Glenn for coming down to help me try and sort the issue with my car, unfortunately we didnt manage to resolve the issue but we can confirm that my MAF is OK and that the fault still occurs even in 'stock' mode.

Next step is to replace the Pre-CAT Lambda probe I think!

 

[vern]

A massive thanks to Glenn for coming down to help me try and sort the issue with my car, unfortunately we didnt manage to resolve the issue but we can confirm that my MAF is OK and that the fault still occurs even in 'stock' mode.

Next step is to replace the Pre-CAT Lambda probe I think!

AAARRGGH that's bad luck mate, yep next on list is 02 sensors, 90% maf with that code, as a vac leak gives an addi code ie idle multi is rev range throughout, pi$$ed for ya mate

 

[vern]

Martyn.........

1= Check all conections and pipework after Maf. this will admit unmetered air and make you lean, check and doulble check all vac lines, to DV, and around FPR, also under engine cover around N249 valve and res,if your car still has one, check lines to N75 also

2= check your D/P to turbo gasket, for leaks, infact check all hoses and connections underside the lot, and tip on turbo, jubilee's can somtimes bite through

3= replace 02 sensor.........(still cannot believe it was not Maf )

When i,ve looked @ your block 032 some of 1st 02 sensor's are @ 0% this is ideal, i gather this was after reset of codes then creeps back up a+ %%%% is adding fuel to compensate for lean running, sensor could be bad i suppose

You then have to look @ a block fuel filter, or "sagging" fuel pump etc, just cannot seee this as your inj times are low, ecu would make them on longer, as long as wait for it.. MAF was o.k

Get your car to stealth or another good VAG specialist asap, if you dont find owt.....

 

[Martyn]

Martyn.........

1= Check all conections and pipework after Maf. this will admit unmetered air and make you lean, check and doulble check all vac lines, to DV, and around FPR, also under engine cover around N249 valve and res,if your car still has one, check lines to N75 also

2= check your D/P to turbo gasket, for leaks, infact check all hoses and connections underside the lot, and tip on turbo, jubilee's can somtimes bite through

3= replace 02 sensor.........(still cannot believe it was not Maf )

When i,ve looked @ your block 032 some of 1st 02 sensor's are @ 0% this is ideal, i gather this was after reset of codes then creeps back up a+ %%%% is adding fuel to compensate for lean running, sensor could be bad i suppose

You then have to look @ a block fuel filter, or "sagging" fuel pump etc, just cannot seee this as your inj times are low, ecu would make them on longer, as long as wait for it.. MAF was o.k

Get your car to stealth or another good VAG specialist asap, if you dont find owt.....

Cheers Vern.

1. I will shortly be ordering some more silicone hose to so I can finish replacing all of the boost/vac hoses on top of the engine (N249) and inlet (most of them were replaced on friday).

N75 has been thoroughly cleaned and refitted with new hoses so I know the air isnt entering the system there. Forge DV and associated hoses are nipped up nice and tight so I'm pretty sure they're ok too.

2. DP hasnt been on the car long so the gasket *should* be in good nick, bolts should be pretty tight too but I'll get my mechanic to try and get another turn on them when he changes the Lambda probe tomorrow.

However as a side note....I drove home from M0rks with the DP blowing a few weeks back and no codes were thrown

I've checked the TIP and all it's corresponding connections and all seems fine. 'Almost' tempted to put the standard TIP back on to see if the situation is improved but it's a bit of a shitty job.

3. 02 sensor is on order and should be with me tomorrow with any luck.

My MAF ran absolutely fine on Glenns car, no codes, no rough running etc. Figures were almost identical to those Glenn was pulling on his own MAF.

0% Lambda is recorded straight after the fault code is cleared, after 10/15/20 mins of driving it starts to creep up (as per logs) until it reaches the adaption end point of 25% (Limp mode and fault code starts here) The thing which confuses me the most is when Lambda ramps up mainly when cruising with very light throttle (no boost etc).

Bloody cars eh?

 

[Feel]

I'll get in there quick and make myself look clever - the car only uses the the Lambda probe when cruising as it uses it in a closed loop scenario. It's does this for emissions/fuel economy. When you're on full throttle, it goes open loop and just uses the tables in the ECU to figure out how much fuel to chuck in. Max Torque said so, so it must be true

I assume it just uses the MAF when you're on full throttle. So, I'm not THAT clever then.

 

[Martyn]

Feel, good to meet you on thurs mate!

I've PM'd Max_Torque with a pointer to this thread but I'm currently waiting for a response. Hopefully he'll be able to help clear things up.

 

[ibizacupra]

cruising on lambda control yes.. so either a vacuum leak, or manifold/zorst leak pre-lambda probe, or plain poorly lambda probe itself.

You on 3bar reggy or 4bar now?

 

[Martyn]

4bar FPR now fitted Bill, managed to get hold of one at the weekend!

 

[Glenn]

I'll get in there quick and make myself look clever - the car only uses the Lambda probe when cruising as it uses it in a closed loop scenario.

Sorry Martyn, I'm an idiot - I forgot about this. That's why it seemed to adapt faster sometimes than at others - depends on how long we've been in closed loop.

My MAF in your car was heading the same way as with yours towards +25% and limp until we dropped out of closed loop.

Your MAF in my car was trimming the other way -%, the same as mine does. That & the similar flow rate numbers for both cars make me fairly confident that the MAFs are ok. Either that or they're both screwed in exactly the same way?

 

[vern]

I'll get in there quick and make myself look clever - the car only uses the the Lambda probe when cruising as it uses it in a closed loop scenario. It's does this for emissions/fuel economy. When you're on full throttle, it goes open loop and just uses the tables in the ECU to figure out how much fuel to chuck in. Max Torque said so, so it must be true

I assume it just uses the MAF when you're on full throttle. So, I'm not THAT clever then.

Yep phil true, uses 02 upto 2.5k ish revs i think, above uses Maf/Map sensor and tables and a few other sensors play a role too, coolant etc..
Did you fit a new gasket between D/p and turbo, this is pre 02, that's what i was getting @ earlier.......... also revo stage 2 only ignores 2nd sensor for "Cat below effiencey" DTC due to extra fow, also d/p's can pull this code.

 

[Martyn]

Vern, the gasket was a new one at the time of DP fitting bud

 

[vern]

Vern, the gasket was a new one at the time of DP fitting bud

Good lad, obscure one this, or somthing so simple we are idiots like the 02 sensor keep me posted, doing my head in.............